"Depending on how you are going to brew coffee, you need to choose a grind size that will get all of the delicious flavors you want without getting bitterness or sourness you don't."
COFFEE GRINDING PARTICLE SIZE & UNIFORMITY BURR & BLADE GRINDERS
| COFFEE GRINDING |
Whole bean coffee that is freshly roasted and ideally stored is best for brewing at home because it helps retain and preserve all the delicious flavors we want to taste. Coffee must be ground so those flavors are easier to get to, and then hot water is used to wash them out because hot water is great at dissolving these flavors and trapping flavorful gases.
We have to grind the coffee to make these flavors more accessible. Depending on how we are going to extract these flavors, we need to choose a grind size that will get everything we want without getting flavors we don't want, like bitterness or astringency.
We use hot water to wash out flavor molecules capable of being dissolved out of the ground coffee. These flavor molecules are called soluble solids.
| PARTICLE SIZE & UNIFORMITY|
Particle size is extremely important, and one of the important aspect of the grinding process because it dictates how the end result will taste. What is the correct particle size? That depends on which method you are brewing.
As a rule of thumb, the larger the grind size, the more contact time with water for extraction and the smaller the grind, the less time water and grounds should be in contact.
FINE
CONSISTENCY:
FLOUR
METHOD:
ESPRESSO
MEDIUM FINE
CONSISTENCY:
TABLE SALT
METHOD:
AEROPRESS & V60
MEDIUM
CONSISTENCY:
SAND
METHOD:
CHEMEX & DRIP MACHINE
COARSE
CONSISTENCY:
KOSHER SALT
METHOD:
FRENCH PRESS & CLEVER DRIPPER
| BURR & BLADE GRINDERS |
BURR AND BLADE GRINDERS - WHAT'S THE DIFFERENCE?
BURR GRINDERS
When coffee is ground in a burr grinder, only a narrow range of particles can fit between the burrs. This allows you to extract coffee more evenly due to particle size uniformity and consistency.
BLADE GRINDERS
Blade grinders use a blade using high rotation frequencies (sometimes up to 20,000 or 30,000 RPM's) to rapidly chop the beans into smaller particle sizes.
PROS VS. CONS
PROS: Uniform grind size, repeatable grind settings, delivers desired results, minimal friction, less heat from motors.
CONS: Burr grinders tend to be more expensive.
PROS VS. CONS
PROS: They are relatively cheap and widely available.
CONS: Lots of friction, grinding compartment located above motor, blade uses chopping action rather than grinding, inconsistent, impossible to get consistent or desired results.
4 KEY PROBLEMS ASSOCIATED WITH BLADE GRINDERS
FRICTION
Rapidly chopping the beans with rotating metal blades creates a lot of friction. This friction creates quite a bit of excess heat, which in turn, diminishes the freshness and flavors of the coffee.
MOTOR
The grinding compartment usually resides directly above the motor, which gives off a good amount of heat. This adds to the heat caused by friction, again diminishing the freshness of the coffee.
UNEVENNESS
No matter how long you keep the blade going, you will always have a huge variance of particle size. Too many fines will result in an overextracted, bitter brew; too many large pieces, result in underdeveloped, weak and watery flavors.
INCONSISTENCY
It's difficult, if not impossible, to get consistent results. Grinding for a set amount of time every time you brew doesn't necessarily mean you get the same results.